Humidity & Psychrometrics

Relative humidity is a poor guide to how muggy it feels. The dew point and wet-bulb temperature tell the truth about moisture in the air.

Humidity & PsychrometricsLive

dew point, wet bulb, mixing ratio

25°

dry bulb

18°

wet bulb

14°

dew point

These three temperatures fully describe the moisture in the air.

Controls

Presets

Air temperature (°C)

Relative humidity (%)

Relative humidity alone is misleading. The dew point — the temperature at which air saturates — is the honest measure of how muggy it feels and where clouds or condensation form. The wet-bulb temperature, always between dew point and air temperature, is what evaporative cooling can reach and a key limit for human survivability in extreme heat.

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Data Inspector

Dew point13.9 °C

Wet-bulb temp18.0 °C

Mixing ratio9.9 g/kg

Comfortpleasant

Governing equation

W = 622 \frac{p _{w}}{p - p _{w}} = 622 \times \frac{15.8}{1013 - 15.8} \approx 9.9 g/kg

Reading this result: Dew point 13.9 °C sits in the pleasant range; the wet bulb (18.0 °C) marks the coolest that evaporation can reach here.

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How it works

The dew point is the temperature at which air becomes saturated and dew, fog, or clouds form — the honest measure of muggy weather. The wet-bulb temperature, the coldest that evaporative cooling can reach, is a key survivability limit in extreme heat. Together with the dry-bulb temperature, these three values fully describe the air's moisture state used in HVAC and meteorology.

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Frequently asked questions

Is this dew point wet bulb calculator tool really free?▾

Yes. Humidity & Psychrometrics runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

Do I need to install anything?▾

No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.

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How accurate are the results?▾

The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.